One-step synthesis of phosphorus/oxygen co-doped g-C3N4/anatase TiO2 Z-scheme photocatalyst for significantly enhanced visible-light photocatalysis degradation of enrofloxacin

Abstract

Anatase TiO₂ nanoparticles coated with P and O co-doped g-C₃N₄ were prepared via a single-step procedure. The resulting POCN/anatase TiO₂ demonstrated remarkable performance in the degradation of enrofloxacin (ENFX). The photocatalytic activity of this heterojunction was 28.9 and 3.71 times better than that of the CN and anatase TiO₂, respectively. The microtopography of the POCN/anatase TiO₂ was revealed in this study. Co-doping with P and O increased the visible light adsorption capacity of the g-C₃N₄, whereas the anatase TiO₂ nanoparticles enhanced the adsorption properties of the ENFX and the separation of the photoinduced carriers of the POCN/anatase TiO₂. The O₂^·- and h⁺ were the main reactive oxidative species in the photocatalytic degradation of ENFX. The results of the detection of H₂O₂ and ESR confirmed that POCN/anatase TiO₂ was a type Z-scheme photocatalyst. Finally, the ENFX degradation pathways were estimated through the detection of by-products.

Keywords: Anatase TiO(2); Co-doped graphitic carbon nitride; Enrofloxacin; Heterojunction; Reactive species.